Demand for all types of mineral products is accelerating. At the same time, shifts to alternate sources of energy such as use of steam or water at elevated temperatures in situ (associated with "marker rocks") for driving compressors and the like have occurred. Unfortunately, physical properties of economic ore minerals and country or host rock surrounding them are not well defined by conventional surface exploration techniques. Accordingly, the lithology of the earth formation under survey is most difficult to predict under such conditions.
Although in the prior-referenced application, supra, a method is described for accurately mapping shallow formations by means of refractive waves, such method primarily annotates, inter alia, subsurface addresses to observed shear and compressional wave velocities. Lithology was not predicted.